Surgical device for controlled anchoring in the intestine

ABSTRACT

A surgical anchor device for being anchored on the mucous membrane of the inner wall of the intestine, the device having a temporary anchor element presenting anchoring that can be modified in a controlled manner and having a first substantially cylindrical multiply-perforated wall presenting properties of radial elasticity whereby the first wall presents an outer diameter that can be varied in controlled manner, wherein a portion of the inner surface of the first wall is lined with an independent leakproof inner sheath having only its longitudinal ends fastened to the anchor element to define a suction chamber between the inner sheath and the first wall, the temporary anchor element being coupled to a flexible or semi-rigid tube extending outside the anchor element, an open end of the injection-suction tube opening out into the suction chamber enabling air to be injected into or sucked out from the suction chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. application Ser. No.18/312,335, filed May 4, 2023, which is a continuation application ofU.S. application Ser. No. 17/071,034, filed Oct. 15, 2020, which is adivisional application of U.S. application Ser. No. 15/959,553, filedApr. 23, 2018, now U.S. Pat. No. 10,835,248, which is a divisionalapplication of U.S. application Ser. No. 14/234,834, filed Jan. 24,2014, now U.S. Pat. No. 9,980,727, which is a 371 of InternationalApplication No. PCT/FR2012/051576, filed Jul. 5, 2012, which claimspriority to French Patent Application No. 1156771, filed Jul. 25, 2011,the entire contents of each of which are incorporated by referenceherein. This application is also related to U.S. application Ser. No.15/097,491, filed Apr. 13, 2016, now U.S. Pat. No. 10,456,138, which isa divisional application of U.S. application Ser. No. 13/147,199, filedAug. 11, 2011, now U.S. Pat. No. 9,339,272, which is a 371 ofInternational Application No. PCT/FR2010/050210, filed Feb. 9, 2010,which claims priority to French Patent Application No. 0950819, filedFeb. 10, 2009, the entire contents of each of which are incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to a surgical device for anchoring to themucous membrane of the inner wall of the intestine, the devicecomprising an anchor element having at least one first semi-rigid hollowlongitudinal element defining a wall forming a surface of revolutionabout a longitudinal axis with a substantially cylindricalmultiply-perforated main portion of substantially circular sectionreferred to as the “first” wall, said anchor element being made of amaterial giving it radial elasticity properties such that it can becompressed radially into a retracted position and can adopt a saidmaximally radially expanded position after the radial compression hasbeen released, whereby said first multiply-perforated wall presents adiameter that can be varied in controlled manner.

More particularly, the present invention relates to an anchor devicepresenting anchoring that can be modified in controlled manner.

BACKGROUND OF THE INVENTION

Elements for anchoring in the intestine are known, in particular devicesknown as “enteral prostheses” or “digestive stents”, which devicespresent a said first wall formed still more particularly as a mesh ofspiral-wound wires, preferably made of nitinol, presenting properties ofcontrolled diameter variation depending on temperature as describedbelow, with an outer diameter that can be varied in controlled mannerbetween:

-   -   a minimum first outer diameter in said radially retracted        position of said first wall, preferably of at most 10        millimeters (mm); and    -   a maximum first outer diameter in said maximally radially        expanded position of said first wall, preferably lying in the        range 18 mm to 45 mm.

Still more particularly, the present invention relates to a surgicaldevice suitable for providing temporary protection for an anastomosis inthe esophagus, the stomach, the jejunum, the colon, the rectum, or theanal canal.

In WO 2010/092291, and also in other documents such as WO 03/094785 andUS 2008/0208357, said anchor element is coupled to an outer flexiblesheath that extends in the same longitudinal direction as said stent, onthe outside of said stent.

Those devices may be implanted 1) in the small intestine as described inWO 03/094785; 2) in the esophagus as described in US 2008/0208357 tocombat obesity; and 3) in the colon, as described in WO 2010/092291 forprotecting an anastomosis.

In other applications, in particular to avoid proliferation of cancer, asaid stent is used without a said sheath solely for the purposes ofproviding permanent protection of the zone that is covered by saidstent.

In any event, said anchor element must remain anchored in temporary orpermanent manner against the wall of the intestine with said sheathextending downstream from said stent. In all of the applicationsmentioned above, it can happen that said temporary or permanent anchorelements separate from the wall of the intestine and migrate too soon.

In particular in the application of providing temporary protection foran anastomosis as described in WO 2010/092291, provision is made for thetemporary anchorage to begin migrating after the end of thepost-operative ileus period, which is estimated on average to be threedays to five days. As a result, and because said outer sheath presents alength covering the distance between the anastomosis and the anchor sitethat is at least 50 centimeters (cm) upstream, and that is preferably atleast 1 meter (m) upstream, said anchor is thus anchored far enoughupstream from the anastomosis to ensure that when the digestive processrestarts, the time it takes to migrate from said anchor position to saidanastomosis is at least three days, and preferably at least six days.

Thus, insofar as the stage of post-operative intestinal paralysis, knownas “ileus”, lasts for three to five days, it is possible to protect theanastomosis for that same period plus the time taken, after said anchorelement has been released, for it to migrate from its anchor siteupstream from the anastomosis to the site of the anastomosis, it beingunderstood that this migration time depends on the distance to betraveled between the anchor site and the anastomosis. In practice, adistance of 50 cm to 1 m gives rise to a migration time of three days tosix days, such that, in all, the anastomosis is protected for a durationof at least six days and possibly up to 11 days after making theanastomosis.

Nevertheless, it can happen that the post-operative ileus period isexceptionally short or on the contrary exceptionally long, with periodslying in the range 24 hours to four weeks, such that either the devicemigrates through the anastomosis before it has had time to heal, or onthe contrary the device remains anchored in the intestine for too long.

In order to comply with an appropriate period for remaining within theintestine, it is therefore necessary to take account of the movementsspecific to the intestine of the operated patient. The greater theactivity of the intestine, the faster the migration of the device, italso being understood that it is highly recommended to encouragepost-operative intestinal activity in order to improve rapidrehabilitation of the patient.

For curative treatment of anastomotic fistulas after bypass surgery formorbid obesity, US patent No. 2008/0208357 describes a device forprotecting the gastro-jejunal anastomosis. According to that patent, aprotective sheath is secured to the downstream end of a stent. The stentis positioned in the bottom end of the esophagus where it is to remainin place as a result solely of its own characteristics. The protectivesheath passes through the anastomosis and lies in the jejunum. The majordrawback of that device consists in the risk of the stent migrating atan unwanted moment, and thus the risk of the entire device migratinginto the intestine with at best the need to extract the device byendoscopic maneuvers, and at worse the risk of the intestine becomingoccluded or perforated and making further surgery necessary. The risk ofesophagus stents migrating remains significant, being about 20% for allstents.

Furthermore, the device described in the prior art for temporaryanchorage and for protecting an anastomosis cannot prevent anastomoticfistulas arising, which fistulas take considerably longer to heal thanthe time the device remains in the intestine, in other words thetemporary protection device runs the risk of being eliminated longbefore healing of a fistula, if there is one. Under such circumstances,the practitioner needs to make a protective stomy, which greatlydecreases the therapeutic advantage of the device. From the above, itcan be seen that the behavior of a device for providing an anastomosiswith temporary protection, or more generally of a device for providinganchoring in the intestine, depends on factors that vary sufficientlybetween individuals to give it a random character, with the practitionerhaving no means for modifying the behavior of said anchor element onceit has been implanted.

The time the device spends in the intestine depends on many factors suchas the characteristics of the stent (radial opening force, resistance tocompression, adaptability to deformations of the intestine, shape of themesh, covering of its surface, etc.), the passive physical properties ofthe walls of the intestine (viscoelasticity), its dynamic properties(contractility), and also on the consistency of the stools. One of thefactors that governs the behavior of the device is the force of frictionthat exists between the walls of the stent and the intestine. Thegreater the friction force, the slower the movement of the stent.Unfortunately, the coefficient of friction of the inner walls of theintestine is very low because of the presence of water, thus having theconsequence of making it easier for the stent to slide.

This may be compensated in several ways. One consists in increasing thecoefficient of friction of the outer walls of the stent by means of acovering film having adhesive properties. It has been shown that atextured surface, in particular when covered with micro-fibrils canpresent properties of greater adhesion (S. Buhl et al., Humidityinfluence on the adhesion of biomimetic fibrillar surfaces,International Journal of Materials Research, 2009; 100, No. 8: pp.1119-1126). Nevertheless, that does not make it possible to exert directcontrol at will in variable amounts on the device in order to modify itsbehavior. Another method consists in increasing the diameter of thestent. However, apart from the risk of causing traumatic lesions in thewalls of the intestine, that method likewise provides no direct controlover the behavior of the stent. Finally, it is possible to usesemi-resorbable hybrid stents in which the radial force decreasesprogressively as they are resorbed (Y. Shomura, Composite material stentcomprising metallic wire and polylactic acid fibers, and its mechanicalstrength and retrievability, Acta Radiol. 2009 May; 50(4): 355-9).However, once more, the resorption process is not governed by anyexternal action on the intestine, so it does not make it possible toexercise any direct control at will and in varying amounts on the devicein order to modify its anchoring properties.

In other indications, digestive stents are used for remedying digestivestenoses. These may be stenoses of the esophagus, in particular thosecomplicated by tracheal-esophageal fistula, gastric and duodenalstenoses, colonic and rectal stenoses. Some such stenoses can be treatedby bare stents that serve to reduce the risk of migration at the expenseof becoming incrusted in the wall of the intestine. Others are treatedby stents covered in a film that serves to reduce the risk of becomingincrusted at the expense of increasing the risk of migrating.

It is thus still sought to provide a device that makes it possible toavoid the stent becoming incrusted in the walls of the intestine, whilemaking it possible to control the risk of untimely migration.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a device that makes itpossible to control and to modify at will the behavior of the anchorelement in the intestine.

More particularly, the object of the present invention is to provide anovel type of surgical device that makes it possible at will to modifythe duration of the period it remains static, i.e. the time that elapsesbetween the device being put into place in the intestine and beginningto migrate, and/or the time the device remains dynamically in theintestine, i.e. the time that elapses between the beginning of themigration of the device and its elimination from the intestine.

Still more particularly, the object of the present invention is toprovide a device for which migration can be slowed down and/orinterrupted in the event of anastomotic fistulas appearing so as toallow said fistula to heal before said device migrates to the level ofsaid fistula.

To do this, the present invention consists essentially in takingadvantage of the viscoelasticity of the intestine in order to cause itsinner wall known as its “mucous membrane” to be attracted towards theouter wall of the stent. The intestine or mucous membrane is flexibleand elastic, whereas the walls of the stent are relatively rigid. Theintestine wall can be attracted (by suction) so as to be placed adjacentto the outer walls of the stent under the effect of negative pressure inthe interface between the stent and the mucous membrane. Under suchcircumstances, the force of friction between the intestine and the stentincreases rapidly and significantly by a kind of suction cup effect.Conversely, in the present invention, this suction effect can bemodified or eliminated by injecting air or a liquid solution between thestent and the mucous membrane of the intestine. Consequently, themobility of the stent becomes closely tied to the suction effect, andmodulating that effect then makes it possible to act on the behavior ofthe stent in the intestine.

More precisely, the present invention provides a surgical anchor devicesuitable for being anchored in the mucous membrane of the inner wall ofthe intestine, the device comprising a temporary anchor element ofanchoring that can be modified in controlled manner, comprising at leasta first semi-rigid hollow longitudinal element defining a wall in theform of a surface of revolution about a longitudinal axis having asubstantially cylindrical multiply-perforated main portion ofsubstantially circular section referred to as a “first” wall, said firsthollow longitudinal element being made of a material that gives itproperties of radial elasticity such that it can be compressed radiallyinto a retracted position and can adopt a said position referred to as amaximally radially expanded position after the radial compression hasbeen released, whereby said first multiply-perforated wall presents afirst outer diameter that can be varied in controlled manner between:

-   -   a minimum first outer diameter in said radially retracted        position of said first wall of at most 20 mm, preferably of at        most 10 mm; and    -   a maximum first outer diameter in said maximally radially        expanded position of said first wall, preferably lying in the        range 18 mm to 45 mm;    -   the device being characterized in that at least a portion and        preferably all of the length of the cylindrical inner surface of        said first wall is lined with an independent leakproof layer        forming an inner sheath, only the longitudinal ends of said        inner sheath being fastened in leaktight manner to said anchor        element with the help of first leaktight fastener means,        preferably respective annular elastomer adhesive gaskets, at        each of said longitudinal ends of said inner sheath, so as to        define a chamber referred to as a suction chamber between said        inner sheath and said first wall, said temporary anchor element        being coupled to a flexible or semi-rigid tube referred to as an        injection-suction tube extending outside said anchor element, an        open end of said injection-suction tube opening out into said        suction chamber.

More particularly, said injection-suction tube is connected, preferablyreversibly, at its free longitudinal end to a connection endpiece,itself connected reversibly or suitable for being connected reversiblywith a device such as a syringe for injecting or sucking air or liquid,said connection endpiece including a shutter device, preferably ananti-reflux valve, and a vacuum indicator device suitable for indicatingthe degree of vacuum in said suction chamber at the other end of saidinjection-suction tube, said indicator device preferably being aballoon.

It can be understood that said device for indicating the extent of thevacuum indicates the extent of the vacuum in said suction chamber whilesaid surgical device of the invention is in place against the inner wallof the patient's intestine, thus making it possible to monitor andcontrol or modify the anchor force of the device of the inventionagainst the wall of the intestine.

It can be understood that said injection-suction tube is a semi-rigidtube made in particular of polyethylene (PE) or of polypropylene (PP),and that it presents a length suitable for remaining in shape andextending inside the intestine from an anal or nasal orifice of thepatient to said anchor element, with the length of saidinjection-suction tube preferably being at least 20 cm, and moreparticularly lying in the range 50 cm to 150 cm, and with the free endof said injection-suction tube outside the patient being connected to adevice for sucking or injecting gaseous fluid or liquid, in particularair or a cold liquid as explained below.

It can be understood that said chamber defines a leaktight chamberbetween the leakproof film of the inner sheath and the wall of theintestine when said anchor element is in its maximally expanded positionand is held stationary by being anchored against the inner surface ofthe wall of the intestine. In the event of said anchor element beingreleased and/or in the event of said anchor element migrating tooquickly inside the intestine, said chamber loses its leaktightness.However, it is then possible to suck air through said tube from its freeend outside the patient in order to attract the wall of the intestine bysuction against the outer surface of said first wall of part or even allof the outer surface of said first wall defining said chamber in orderto slow down migration of the anchor element and possibly even to holdit in place and reestablish a vacuum in said chamber, and thusreestablish leaktightness of said chamber.

Conversely, in order to cause the anchor element to migrate and/or inorder to accelerate its migration, it is possible to inject air or aliquid solution into the suction chamber by using said injection-suctiontube.

When using stents made of nitinol, the shape memory of that alloy makesit possible to change the shape and the stiffness of the alloy as afunction of ambient temperature. More particularly, at ambienttemperatures situated below 15° C., nitinol becomes flexible andmalleable. Thus, injecting a cold liquid at a temperature in the range0° C. to 15° C. into the suction chamber makes it possible to make thestent malleable and thus facilitates moving it as it passes through theanastomosis or a zone of narrowing, for example.

The term “first leakproof fastener means” is thus used to mean that saidmeans extend annularly all around the perimeter of said inner sheath incross-section at its longitudinal ends, and constitute leaktight lateralwalls for defining said chamber, where applicable around saidinjection-suction tube passing through said first leaktight fastenermeans, as explained below.

Concerning said anchor element, and in known manner, the following termsare used as follows:

-   -   “semi-rigid” means that said first wall of said anchor element        remains in each of its retracted or expanded positions in a        given shape defining a said surface of revolution; and    -   “outer diameter that can be varied in controlled manner” means        that the diameter of said first wall may be varied in determined        manner as a function of the conditions in which the device is        used, regardless of whether this involves parameters such as        temperature, and/or independent mechanical means co-operating        with said anchor element such as an instrument for putting it        into place, and in particular an “introducer” as explained        below. Preferably, said inner sheath is constituted by a        leakproof film (i.e. having no perforations) that forms a        flexible tubular wall.

This embodiment makes the device easy to fabricate and also providesgreater sensitivity and greater uniformity in the modulation of thesuction effect on injecting/sucking air or liquid through saidinjection-suction tube.

Nevertheless, in another embodiment, said inner sheath may be formed bya second semi-rigid hollow longitudinal element defining a second wallpresenting properties similar to said first hollow longitudinal elementas explained below. Under such circumstances, said injection-suctiontube is interposed between said multiply-perforated first wall and asecond wall that is leakproof or multiply-perforated but covered in aleakproof film on its outer surface.

In a preferred embodiment, the end of said injection-suction tubeopening out into said chamber is constituted by a multiply-perforatedtube portion extending inside said chamber, preferably substantiallyover the entire length of said chamber, also preferably in the form of aZ-shaped line running substantially helically along said suction chamberand stuck to the inner surface of said anchor element.

It can be understood that, at its end situated in the suction chamber,the injection-suction tube is provided with multiple lateralperforations.

This embodiment is preferred since it makes it possible to manage thepressure in said suction chamber in more uniform manner over its entirelength. The Z- (or zigzag) shape of the injection-suction tube enablesit to be folded up in more compact manner when shrinking the diameter ofsaid first wall or of said second wall of the anchor element.

According to another characteristic that is particularly advantageousfor ease of fabricating the device, the end of said injection-suctiontube opening out into said suction chamber passes in leaktight mannerthrough one of said first fastener means, preferably a said annularadhesive gasket, at one of the longitudinal ends of said inner sheath.

The term “passes in leaktight manner through” is used to mean that theconnection between the outer surface of the tube and the orifice viawhich it passes through said first fastener means or said inner sheath,is leaktight.

For numerous applications in particular to protecting anastomoses, thedevice advantageously further includes an outer sheath having a tubularwall constituted by a flexible film fastened to said anchor element atone of the longitudinal ends of said anchor element. More preferably,for reasons of ease of fabrication, said outer sheath constitutes anextension of said inner sheath extending outside said anchor element, inparticular in the longitudinal direction thereof, and still moreparticularly, downstream therefrom.

The term “outer sheath” is used herein to mean a sheath that extendsoutside said anchor element. However, in another embodiment, the innersheath and the outer sheath may be made of two different elastomermaterials.

Said inner and outer sheaths may be two portions of a single sheath.

When the device of the invention is implanted in the esophagus, asdescribed in US 2008/0208357, the injection-suction tube extends outsidethe stent, upstream therefrom, while said outer sheath always extendsdownstream from the stent. The injection-suction tube runs along thelumen of the esophagus towards the oropharynx, passes into one of thenasal cavities, and leaves through the corresponding nasal orifice. Thepath of the injection-suction tube is the path followed by thenaso-gastric suction tube always put into place through the anastomosisin order to suck up digestive secretions and avoid air accumulating inthe stomach during the post-operative stage. The device of the presentinvention enables the device to be retained in the esophagus by theabove-described suction effect.

The device of the present invention may also be used after resection ofthe middle and bottom thirds of the esophagus, and after total orpartial resection of the stomach for various pathologies, and inparticular neoplastic pathologies. Eso-gastric anastomoses orintra-thoracic eso-colonic anastomoses involve a considerable risk offistulas having severe septic consequences in the interpleural space,representing the main cause of death in these post-operative patients.

In other applications, in particular for devices for providing temporaryprotection of anastomoses in the colon, where the injection-suction tubeis inserted via the anal orifice and not via the nasal cavity or themouth cavity, said injection-suction tube and said outer sheath extendoutside said anchor element from the same end of said anchor element andpreferably said injection-suction tube and said outer sheath are securedto each other.

The securing of the injection-suction tube against the wall of saidouter sheath, in particular by adhesive, avoids it becoming twistedagainst itself and/or turning one over the other giving rise to knots orother obstacles to proper extension of said tube and/or of said outersheath outside said anchor element.

Also preferably, said injection-suction tube is situated outside saidouter sheath, i.e. on the outside in the radial direction incross-section, in this example.

This embodiment is preferred since it makes it possible to handle thetube more easily than if it were situated inside said outer sheath, notto mention the hindrance that would arise from interference with theorganic material passing along the inside of said outer sheath once thedigestive process has restarted.

In a variant, said injection-suction tube is incorporated within thetubular wall of said outer sheath.

In an advantageous embodiment, the device of the invention ischaracterized in that said anchor element includes a second semi-rigidhollow longitudinal element defining a wall in the form of a surface ofrevolution around said longitudinal axis (XX) having a substantiallycylindrical multiply-perforated main portion of substantially circularsection referred to as a “second” wall, said second wall being arrangedcoaxially inside said first wall, the longitudinal ends of said secondwall being fastened in leaktight manner to the ends of said first wallwith the help of first or second leaktight fastener means, preferablyrespective annular elastomer adhesive gaskets at each of saidlongitudinal ends of said second wall, said second hollow longitudinalelement being made of a material giving it properties of radialelasticity such that it can be compressed radially into a said retractedposition and can adopt a said maximally radial expanded position wherebysaid second outer diameter of said second wall can vary in controlledmanner between:

-   -   a minimum second outer diameter (D2′) in the radially retracted        position of said second wall that is less than said minimum        first outer diameter; and    -   a maximum second outer diameter (D2) in the maximally radially        expanded position of said second wall that is less than said        maximum first outer diameter.

More particularly, said second multiply-perforated wall is interposedbetween said inner sheath and said first wall, the end of saidinjection-suction tube preferably opening out into said suction chamberbetween said inner sheath and said second wall.

In an embodiment, the spacing between said maximum second outer diameterand said maximum first outer diameter is at least 0.2 mm, preferablylies in the range 0.2 mm to 10 mm, and more preferably in the range 1 mmto 5 mm.

In another embodiment, said second wall is covered in said inner sheath,with said, preferably multiply-perforated, open end of saidinjection-suction tube being interposed between said multiply-perforatedfirst wall and the multiply-perforated second wall covered in saidsheath, said sheath possibly covering the outer surface or preferablythe inner surface of said second wall.

In a particular embodiment, said first wall presents:

-   -   a) a length of at least 30 mm, preferably lying in the range 40        mm to 150 mm, and an outer diameter that may be varied in        controlled manner between a minimum outer diameter in the        radially retracted position of said first wall of no more than        10 mm, and a maximum outer diameter in the maximally radially        expanded position of said first wall lying in the range 18 mm to        45 mm, preferably in the range 20 mm to 35 mm; and    -   b) preferably, at least one of its longitudinal ends, more        preferably its upstream end, having a flared extension referred        to as a “collar”, defining a wall in the form of a surface of        revolution about said longitudinal axis with a circular section        of increasing diameter, having a length preferably lying in the        range 5 mm to 30 mm, more preferably in the range 15 mm to 20        mm, and a maximum diameter equal to at least 105% of said        maximum first diameter and preferably lying in the range 105% to        150%, in particular with DO lying in the range 20 mm to 40 mm.

This embodiment is particularly advantageous, in particular when theouter face of the first wall is covered in a multiply-perforatedelastomer layer, since the function of the collar is to slow down themigration of the device inside the intestine, even after it has ceasedto be anchored against the inner wall of the intestine via its mainlongitudinal portion or outer surface of its first wall, in particularonce the digestive process has restarted.

In a preferred embodiment, said second hollow longitudinal elementincludes a second wall fitted against the inner surface of said firstwall, said first and second walls preferably being of the same length.

This embodiment is preferred since said anchor element as constituted inthis way by two stents exerts increased radial force so that it remainsanchored against the wall of the intestine during a period that issufficiently long after post-operative restarting of the digestiveprocess. This appears to result from the fact that the two stentssecured together serve to stiffen said anchor element overall.Furthermore, the thickness of said first and second walls as juxtaposedin this way creates sufficient spacing between said inner sheath and thewall of the intestine to avoid the perforations of the injection-suctiontube in said suction chamber becoming clogged by the inner sheath beingstuck against said wall of the intestine, as mentioned above.

It can be understood that this embodiment presents the advantage ofpermanently maintaining an annular separation space between said innersheath and said wall of the intestine, resulting from the spacingbetween the first and second walls, thus making it easier to control theextent of the vacuum in said suction chamber. Since said inner sheath isa leakproof flexible film, it can be difficult to separate it uniformlyfrom the wall of the intestine, should that be necessary as a result ofan excessive suction effect.

Also preferably, each said first and second hollow longitudinal elementincludes at one of the longitudinal ends of each said first and secondwalls respectively a flared extension referred to as a “collar”,defining a surface of revolution about said longitudinal axis (XX) witha circular section of diameter that increases from the end of said firstor second wall towards the end of the corresponding said first or secondhollow longitudinal element, and of maximum diameter (DO) equal to atleast 105% of said maximum first diameter (D1) and preferably lying inthe range 105% to 150%, said two hollow longitudinal elements beingengaged one inside the other and head to tail so that said anchorelement has a said collar at each of its longitudinal ends.

It can be understood that the two stents are engaged one inside theother via their ends that do not have collars.

Such a collar makes it possible to obtain a larger diameter over ashorter length and thus to obtain better adhesion while limiting therisk of perforating the intestine.

Shim et al. have described a technique for treating neoplastic stenosesof the colon using two coaxial stents engaged one within the other (C.S. Shim et al., Double colonic stenting in proximal malignant colonicobstruction, Endoscopy 2004; 36: 426-431). That involves two individualstents, put into place in the lumen of the colon, separately and oneafter the other, each by means of its own introducer. Moon et al. havealso reported experiments with a double stent based on nitinol (C. M.Moon et al., Comparison of a newly-designed double-layered combinationcovered stent and D-Weave uncovered stent for decompression ofobstructive colorectal cancer: a prospective multicenter study, DisColon Rectum 2010; 53: 1190-1996). The two stents are identical, beingfabricated from a two-strand nitinol wire with open mesh without anysecuring element between the two stents, thereby conferring a largeamount of radial and longitudinal deformability thereto and making themeasier to introduce into the 3 mm operator canal of the coloscope. Anon-perforated film is interposed between the two stents. The outerstent serves to provide good incrustation against the wall of theintestine, while the inner stent is covered in a layer of anon-perforated film that prevents the tumor proliferating inside theinner stent and thus preserves an unobstructed passage inside the innerstent. In contrast, those prior art double stents do not define asuction chamber in accordance with the present invention and/or they donot co-operate with a said injection-suction tube, suitable forcontrolling the anchor properties and/or the migration of said anchorelement from outside. Furthermore, the two stents of the presentinvention are preferably single-strand stents with securing elements andwith practically no longitudinal deformation, as explained below.

In an embodiment, said outer sheath is stuck to the inner face of thedownstream collar. In another embodiment, the inner surface of one ofthe two collars is covered in a biocompatible non-perforated leakprooffilm.

Still more particularly, said outer sheath at rest presents a lengthdownstream from said anchor element of at least 50 cm, preferably of atleast 1 m, with an outer diameter lying in the range 18 mm to 45 mm, andpreferably in the range 20 mm to 35 mm.

That device is particularly useful for providing temporary protection ofan anastomosis in the colon, the rectum, or the anal canal.

Under such circumstances, and in known manner, the smaller outerdiameter D′1 in the radially retracted position of said first wallenables said anchor element to be inserted anally in said radiallyretracted position and then taken along the colon to a temporary anchorposition upstream from the anastomosis in the colon, the rectum, or theanal canal. The maximum outer diameter D1 in the maximally radiallyexpanded position of said wall enables said anchor element to remainanchored temporarily, being held by the radial expansion force againstthe wall of the intestine in the absence of any matter passing along theintestine, and is suitable for being released and for starting tomigrate when the intestine contracts and expands during so-called“peristalsis” once the digestive process has restarted.

It can be understood that said anchor element may then adopt:

-   -   a small outer diameter D′1 of said first wall that is at least        less than the diameter of the intestine at rest, and preferably        less than 10 mm, so as to be suitable for being introduced        anally to upstream of an anastomosis in the intestine; and    -   a maximally radially expanded outer diameter D1 of said first        wall that is greater than or equal to the diameter of the        intestine at rest so as to be capable of being anchored        temporarily by pressing against the wall of the intestine as a        result of the radial expansion of at least a portion of said        anchor element, where D1 is nevertheless smaller than the        maximum diameter of the intestine when working in peristalsis so        that said anchor element remains fastened against the wall of        the intestine in the absence of any matter passing along the        intestine, in particular during the post-operative stage of        intestinal paralysis known as ileus, but is no longer fastened        to the intestine and in practice begins to migrate when the        digestive process restarts, the device sliding along the wall of        the intestine.

One conventional way of determining D1 is to calibrate the section ofone of the ends of the intestine by means of instruments referred to as“bougies” and commonly used by surgeons. Another way of determining D1is to consider it as being equal to the diameter of the circular staplerinserted for making the mechanical anastomosis, where applicable. Undersuch circumstances, D1 may more particularly lie in the range 18 mm to33 mm, corresponding to the outside diameters of the staples that arecurrently commercially available.

The term “longitudinal end” is used to mean an end in the longitudinaldirection of said anchor element or, where appropriate, of said outersheath.

The term “at rest” when used concerning the length and the diameter ofthe outer sheath refers to its length and diameter when its elasticityis not involved, respectively in the longitudinal and radial directions.

After the digestive process has restarted, peristalsis of the intestinecauses said anchor element to be released and to migrate, however theradial expansion properties of the anchor element enable its outer wallto continue sliding in contact with the inner wall of the intestine andalso to obtain sufficient leaktightness to prevent the fecal bolus frompassing between the outer wall of the anchor element and the inner wallof the intestine, thereby continuing to protect the anastomosis. It isessential for the fecal bolus to pass inside the outer sheath and to bekept well separated from the walls of the intestine in the vicinity ofthe anastomosis.

The values given above for the diameter in radial expansion of theanchor element correspond to values that are slightly greater than thediameter of the intestine at rest in some individuals, but less than the30 mm to 60 mm value of the maximum diameter of the intestine asexpanded during the digestive process. In addition, the length of saidmain portion is such that the contact area between said anchor elementand the wall of the colon combined with the radial expansion force aresuch that said anchor element in the maximally expanded position issuitable for remaining stationary temporarily as a result of its radialexpansion force against the wall of the intestine upstream from theanastomosis, so it does not migrate for at least three days andpreferably for five days after it has been anchored and in the absenceof the digestive process. If the main portion does not have a length ofat last 30 mm in contact against the colon, then said anchor elementcannot remain anchored for at least three days without having recourseto fastener means, thus requiring means and/or surgery to deactivatethose fastener means and allow the element to migrate, or without havingrecourse to anchor means that present a maximally expanded diameter thatis greater and that could injure the colon and above all that couldprevent the anchor element being released naturally when the digestiveprocess restarts.

Furthermore, the length of the outer sheath is such that the distancebetween the anastomosis and the anchor site upstream therefrom may be atleast 20 cm, and preferably at least 50 cm, and said anchor element maybe anchored in the colon far enough upstream from the anastomosis sothat when the digestive process restarts, the time it takes to migratefrom said anchor position to said anastomosis is at least three days andpreferably at least six days, with said outer sheath protecting theanastomosis and possibly extending beyond the anal orifice when saidanchor element is in the anchor position.

Thus, insofar as the stage of post-operative intestinal paralysis knownas “ileus” lasts for three days to five days, it is possible to protectthe anastomosis for this same period plus the length of time taken,after said anchor element has been released, for it to migrate from itsanchor site upstream from the anastomosis to the site of theanastomosis, it being understood that this migration time depends on thedistance to be traveled between the anchor site and anastomosis. Inpractice, a distance of 50 cm to 1 m leads to a migration time of threedays to six days, such that the anastomosis is protected in all for aduration of at least six days and up to 11 days after the anastomosis ismade.

Advantageously, said inner and outer sheaths (7) are made ofbiocompatible synthetic material, having a wall thickness of 0.01 mm to1 mm, preferably being made of silicone or polyurethane type elastomermaterials having thickness in the range 0.05 mm to 1 mm, and morepreferably presenting properties of radial and longitudinal elasticity,and at least said outer sheath presenting shape memory properties andnon-stick properties.

It can be understood that by being made of elastomer, said outer sheathpresents properties of being radially and longitudinal stretchable thatare similar to those of the wall of the intestine, which properties arethose of an elastomer material forming said outer sheath, which presentsproperties of radial and longitudinal elasticity. These properties ofradial and longitudinal elasticity of the outer sheath are similar tothose of the wall of the colon and thus allow matter to pass through theintestine properly inside said outer sheath throughout the entireduration of the migration of the anchor element, i.e. a duration of atleast six days and up to ten days.

The longitudinal elasticity of the elastomer outer sheath may be greaterthan that of the intestine without giving rise to any difficulty, indeedthat presents the advantage of it being possible to pull on the portionof the outer sheath that has passed through the anus so as to cut offthe end of the sheath, which then retracts back inside upstream in therectum.

Because of its radial elasticity, said longitudinal end of the outersheath remains fastened to said end of said anchor element regardless ofthe extent to which it has been expanded radially.

Furthermore, the thickness characteristics of the outer sheath incombination with its elasticity give it a shape memory property. Theterm “shape memory property” is used herein to mean that the elastomermaterial constituting said outer sheath naturally returns to its initialshape after it has been deformed in folding. Given the great length ofthe outer sheath, these shape memory properties are important so thatthe material naturally returns to its longitudinal shape withoutcreating any blockage to the passage of material through the intestinein the event of the outer sheath becoming folded, as can happen duringits migration after the release of the anchor element.

The term “non-stick properties” is used to mean that the elastomermaterial constituting said outer sheath presents a coefficient ofadhesion such that the two opposite surfaces of the inner wall of theouter sheath do not stick to each other in the event of folding, so asto ensure that no resistance is created against passing gas and matter.

Said anchor element may be held in its radially retracted position withan instrument referred to as an “introducer” and described below, withradial expansion taking place after the anchor element has separatedfrom the introducer.

It can also be understood that:

-   -   said outer sheath presents a diameter at rest that is        substantially not less than said small outer diameter D′1 of        said hollow anchor element when it is radially retracted, and        less than the diameter of the intestine at rest, and preferably        said diameter at rest of said outer sheath is substantially        equal to the diameter at rest of the wall of the intestine at        rest; and    -   said outer sheath extends downstream from the end of said anchor        element to which it is fastened over a length corresponding to        the distance between the anchor position upstream from said        anastomosis and a downstream position preferably going as far as        the anal orifice.

Said first wall, and where appropriate said second wall, of said anchorelement are multiply-perforated, in particular by pores ormini-perforations.

In a particular embodiment, said first and second hollow longitudinalelements for temporary anchoring are stent type enteral prostheses.

Said first tubular wall may be covered over at least its outer face in amultiply-perforated covering made of biocompatible synthetic material,preferably an elastomer of the silicone or polyurethane type. This outercovering is doubly advantageous in that it makes it easier to releasesaid anchor element by sliding along the wall of the intestine when thedigestive process restarts, and during anchoring it protects the wall ofthe intestine against which said longitudinal element has expanded,which might otherwise give rise to incrustation in the tissue of thewall and prevent subsequent release, or possibly even lead toperforation of the wall of the intestine.

Such enteral prostheses of the type known as “stents” have been usedwith intestinal tumors for about 20 years, namely for palliativetreatment of tumoral stenoses (narrowings) of the esophagus, of theduodenum, and of the colon.

Said temporary anchor element is preferably constituted by one or moreenteral prostheses formed by an open mesh of spiral-wound metal wires orplastics filaments, in particular based on polyethylene, and possiblycovered in a layer of biocompatible synthetic material covering saidmesh, said covering preferably being made of a biocompatible elastomermaterial such as silicone.

In known manner, radial expansion is then the result of the crossing ofthe metal wires with angle variation making it possible to vary thewidth of the lozenges or parallelograms of the meshes of said mesh ofspiral-wound wires.

Preferably, and in known manner, a stent is used of a design and a shapefor the spiral-wound wire mesh that makes it possible to obtainvariation in the diameter of said stent with minimum variation in itslength, preferably with practically no variation in its length on beingcompressed radially.

Advantageously, said anchor element is made of a material that gives itsaid ability to expand by radial elasticity only at a temperature thatis not less than ambient temperature (20° C.), and in particular at thetemperature of the human body, said anchor element being in saidretracted radial position at a temperature lower than said ambienttemperature, and preferably lower than 5° C. It can be understood thatthe material of tubular shape changes diameter automatically as afunction of ambient temperature.

Still more particularly, said anchor element is made up of one or moreenteral prostheses formed by a mesh of spiral-wound wires, preferablymade of nitinol.

Nitinol is a metal alloy presenting radial expansion properties thatvary progressively as a function of temperature at a temperature greaterthan or equal to ambient temperature (25° C.), thus enabling it toconserve its retracted shape at colder temperatures, in particular at 4°C. during storage. Once retracted at low temperature, it thus remainsretracted for a length of time that is sufficient to enable it to bemoved into the intestine with the help of said introducer. Once it hasbeen released inside the intestine, the prosthesis progressively expandsradially under the effect of higher ambient temperature, i.e. thetemperature of the human body.

More particularly, the thickness of said first wall of the anchorelement lies in the range 0.1 mm to 1 mm, and preferably in the range0.2 mm to 0.5 mm.

This is more particularly the thickness of the wire forming said firstwall when it is constituted by a stent made of a mesh of spiral-woundwires.

In order to satisfy the radial expansion properties of the elastomersheath, and given the thicknesses involved (0.01 mm to 0.1 mm), it isnecessary to use elastomer compositions that present a certain amount ofhardness, and also a certain coefficient of adhesion, and a certainamount of shape memory (compression set), with values that are selectedto lie within ranges that are specified below.

More particularly, said outer sheath at least and preferably both saidinner and outer sheaths is/are made of biocompatible polymer materialbased on elastomer that is preferably of the silicone type and/or of thepolyurethane type, and presenting the following properties:

-   -   hardness on the Shore A scale lying in the range 5 to 95, and        preferably in the range 50 to 70;    -   compression set lying in the range 10% to 35%, preferably in the        range 17% to 23%; and    -   coefficient of friction lying in the range 0.30 to 0.90,        preferably in the range 0.35 to 0.45.

The term “hardness” is used to mean the elastic deformation energy of anelastomer expressed on the Shore A scale, e.g. in accordance with theDIN 53505 standard.

The term “compression set” is used to mean the residual deformation thatremains after a sample of elastomer has been relieved of a load that hasbeen applied for a determined length of time in compliance with the testof the DIN 53517 ISO 815B standard, e.g. the property of shape memory onfolding, the material returning to an unfolded shape as soon as thecompression that gave rise to the folding is released.

The term “coefficient of friction” may be measured using the ASTM D1894standard, for example.

The above-mentioned values for the coefficient of friction ensure thatthere is no adhesion between the two opposite faces of the inner wall ofthe sheath, one to the other, so as to avoid creating any resistance tothe passage of gas or of matter through the sheath, and also to ensurethat in the event of the sheath folding it does not become blocked byclosing on itself.

Still more particularly, said sheath is made of a biocompatible polymermaterial based on silicone comprising at least the following compounds:

-   -   an elastomer having the liquid silicon rubber (LSR) grade or        quality in a proportion by weight lying in the range 75% to 95%;    -   an elastomer having the room temperature vulcanizing (RTV) grade        or quality in a proportion by weight lying in the range 2.5% to        12.5%; and    -   an elastomer having the gel grade or quality in a proportion by        weight lying in the range 2.5% to 12.5%.

This combination of elastomers of different grades (LRS+RTV+gel) isadvantageous because:

-   -   an elastomer of the LSR grade or quality provides resistance to        tearing;    -   an elastomer of the RTV grade or quality provides properties of        radial and longitudinal elasticity; and    -   an elastomer of the gel grade or quality provides a small        coefficient of adhesion (non-stick).

In an embodiment, said anchor element is an enteral prosthesis of thestent type covered on at least its outer face in a multiply-perforatedcovering of an elastomer synthetic material of the silicone orpolyurethane type, said elastomer covering, where applicable, being moreflexible than the elastomer material constituting said sheath, theconnection between said sheath and said anchor element being by saidanchor being overlapped by said sheath over a fraction only of thelength of said anchor element.

Stent type enteral prostheses of this type that are covered inelastomer, in particular in a silicone-based elastomer, are well knownand commercially available.

Thus, the elastomer covering the stent presents greater radial andlongitudinal deformability than does the elastomer of the sheath, i.e.the elastomer of the covering of the stent is constituted, whereappropriate, by a mixture of different types of silicone that presents acontent by weight of the RTV grade that is greater than the content ofthe elastomer of the sheath, while still remaining within theabove-mentioned range of 2.5% to 12.5%.

As explained below, this embodiment makes it possible, by exertingtraction on the sheath, to reduce the diameter of the stent and tolengthen it axially, thereby enabling it to be separated from theintestine in order to facilitate its migration through the anastomosiswhen said anchor element is released.

The coefficient of friction of the outer surface of the anchor elementmay be increased by means of a covering film having adhesive properties,presenting an outer surface that is textured, in particular beingcovered in micro-fibrils, as described above.

Also advantageously, a said anchor element of the stent type is usedthat has an elongate or filiform extension at its end, referred to inconventional manner as a “lasso”, which extension enables traction to beapplied to the end of said stent type anchor element in a manner that isknown to the person skilled in the art, possibly using a tool such as acoloscope, for the purpose of facilitating release and/or migrationthrough the zone of the anastomosis when that is desired, in order toavoid blockage of the element.

Advantageously, said polymer material of said sheath includesradio-opaque filaments, in particular made of barium sulfate, that arearranged in the longitudinal direction of the tube.

These filaments make it possible to follow the migration of the tube ofthe sheath and to monitor its initial position and then its progressivemigration while it is being eliminated. Furthermore, the longitudinalpositioning of such filaments also gives the sheath resistance tolengthening, thereby reducing its longitudinal elasticity, which can beexcessive relative to that of the intestine, as explained above.

Advantageously, the sheath is graduated in the increasing directionstarting from its upstream end.

More particularly, the introducer may, in known manner, be constitutedby a semi-rigid guide tube of the catheter type that is provided at oneof its ends with a handle and that has an inside diameter and a lengththat make it possible to keep said anchor element housed therein in itsretracted shape together with said sheath, which is preferably deployedlongitudinally.

For introduction by the anal passage, said device preferably alsocomprises an instrument known as an introducer and comprising:

-   -   a tubular outer shell suitable for containing and holding said        anchor element compressed in said retracted position and said        injection-suction tube inside the distal end of said outer        shell, and long enough also to contain said sheath and said        injection-suction tube, said outer shell preferably having a        length of at least 70 cm, and more preferably of at least 100        cm;    -   means for bringing the distal end of said introducer from the        anal orifice to said anchor site in the intestine upstream from        the anastomosis; and    -   preferably, means for separating said anchor element from the        outer shell, more preferably consisting in a pusher tube        carrying an abutment at its distal end, where appropriate in        contact with the longitudinal end of said anchor element, said        sheath downstream from the anchor element surrounding said        pusher tube inside said outer shell.

The withdrawal of the outer shell, and then of the pusher tube makes itpossible to deploy the sheath completely downstream from the anchorelement without the surgeon needing to perform any additional maneuverto deploy the sheath.

Also preferably, the device of the invention has a protective tubehaving a portion of curved shape matching the curvature of the concaveside of the sacrum, rigidity greater than that of the outer shell of theintroducer, an outside diameter and a length suitable for enabling saidprotective tube to be inserted via the anal orifice and to extend fromthe anal orifice to upstream of said anastomosis, and an inner diameterand a said curvature matching the curvature of the concave side of thesacrum, such that said protective tube is suitable for containing saidintroducer and for allowing it to be moved from the anal orifice to saidanastomosis, preferably a protective tube having an outer diameter lyingin the range 20 mm to 40 mm and a length lying in the range 10 cm to 25cm.

The present invention also makes it possible to use a surgical device ofthe invention to perform a surgical treatment method in which thefollowing successive steps are performed:

-   -   1) inserting a said surgical device by an anal or nasal passage        and taking it to an anchor site in the intestine, said anchor        element being held in said radially retracted position D′1 and        moved with the help of an instrument known as an introducer, and        said injection-suction tube being of a length not less than the        distance between the anchor site and the anal or nasal orifice;    -   2) separating the introducer from said anchor element once it        has been taken to said anchor site so as to enable said anchor        element to adopt a said anchor position against the wall of the        intestine in said maximally radially expanded position;    -   3) where appropriate, sucking air from the free end of said        injection-suction tube outside the patient in order to prevent        said anchor element from migrating and/or in order to slow down        migration of said anchor element; and    -   4) where appropriate, injecting air and/or a liquid into the        free end of said injection-suction tube, in particular injecting        a cold liquid, in order to facilitate and/or accelerate        migration of said anchor element in the intestine.

In above step 1), said elastomer outer sheath is of a length not lessthan the distance between the anchor site and the anal orifice or of alength of at least 10 cm downstream from the anchor site in theesophagus, said length preferably lying in the range 20 cm to 50 cm.

The method is useful in particular for providing temporary protection ofan anastomosis in the large intestine or colon, the rectum or analcanal, in order to prevent or reduce any risk of anastomotic fistula.Under such circumstances, and preferably, the distance between saidanchor position upstream from said anastomosis and said anastomosis isnot less than the distance traveled in at least three days andpreferably in at least five days by said anchor element during itsmigration once it has been released from said wall of the intestine as aresult of the digestive process restarting.

More particularly, the distance between the anastomosis and said anchorsite is at least 20 cm, and preferably at least 50 cm.

Said introducer is preferably introduced into the anal orifice by beingpushed along the inside of a semi-rigid protective tube having a curvedportion matching the curvature of the concave side of the sacrum, therigidity of the tube being greater than that of the outer shell of theintroducer, said protective tube having an outer diameter and a lengthmaking it suitable for being introduced via the anal orifice so as toextend from the anal orifice to a point immediately upstream from saidanastomosis, and having an inner diameter and a said curvature matchingthe curvature of the concave side of the sacrum, such that saidprotective tube is suitable for containing said introducer and forenabling it to be taken from the anal orifice to said anastomosis, whichtube extends from the anal orifice to said anastomosis, the protectivetube preferably having an outer diameter lying in the range 20 mm to 40mm and a length lying in the range 10 cm to 25 cm.

Also preferably, after said migrating anchor element has been releasedfrom said wall of the intestine as a result of the digestive processrestarting, it is recovered in a semi-rigid protective tube having acurved portion matching the curvature of the concave side of the sacrum,the rigidity of the tube being greater than that of the outer shell ofthe introducer, said protective tube having an outer diameter and alength making it suitable for being introduced via the anal orifice soas to extend from the anal orifice to a point immediately upstream fromsaid anastomosis, and having an inner diameter and a said curvaturematching the curvature of the concave side of the sacrum, such that saidprotective tube is suitable for containing said introducer and forenabling it to be taken from the anal orifice to said anastomosis, whichtube extends from the anal orifice to said anastomosis, the protectivetube preferably having an outer diameter lying in the range 20 mm to 40mm and a length lying in the range 10 cm to 25 cm.

The above-mentioned introducer devices and protective tubes aredescribed in greater detail in WO 2010/092291.

In a preferred embodiment, in particular when said anchor elementincludes a collar, preferably a collar at each end, a yarn referred toas a “lasso” is attached to the margin of said collar, with preferablyat least one of the two yarns being of a length not less than the lengthof said injection-suction tube, and where appropriate of said outersheath.

When protecting an anastomosis with introduction via the anal orifice,the lasso attached to the upstream collar passes through the lumen ofthe anchor element and, where appropriate, of the outer sheathdownstream in order to extend to the outside downstream through the analorifice, said outer sheath being attached to the downstream end of themain portion of said anchor element upstream from the downstream collar,preferably in continuity with said inner sheath.

When protecting the esophagus with introduction via the nasal or mouthorifice, the lasso attached to the upstream collar passes outside saidinjection-suction tube upstream from the anchor element and extends tothe outside through the nasal or mouth orifice, while the lasso attachedto the downstream collar passes:

-   -   either outside the anchor element between the main portion of        said anchor element and the mucous membrane, and then outside        said upstream injection-suction tube in order to pass to the        outside upstream through the nasal or mouth orifice, in the        presence of a downstream outer sheath;    -   or else through the lumen of the anchor element and outside the        upstream injection-suction tube in order to pass to the outside        upstream through the nasal or mouth orifice, in the absence of a        downstream outer sheath.

The advantage of such a lasso is to make it possible to reduce themaximum diameter of the collar and thus the adhesion of the collar onthe mucous membrane by pulling on the end of the lasso, since thecollars are anchored more intimately in the mucous membrane than is themain portion of the anchor element.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the present invention appear inthe light of the following detailed description made with reference toFIGS. 1 to 6 , in which:

FIG. 1 is a diagrammatic longitudinal section view of a device of theinvention comprising a single stent or said first wall and an innersheath constituted by a flexible leakproof film, said outer sheath beingconstituted by a flexible film of the same kind extending said innersheath;

FIG. 1A is a side view of the FIG. 1 device;

FIG. 2 is a diagram in longitudinal section of a device of the inventionin which said inner sheath covers the outer face of a second wall formedby an inner second stent arranged coaxially;

FIG. 3 is a diagram in longitudinal section of a third embodiment of adevice of the invention likewise comprising two coaxial stents, saidinjection-suction tube being interposed between an inner stentconstituted by a flexible leakproof film and a said second wall of theinner stent;

FIG. 4 is a diagram of an embodiment with the anchor element 2constituted by two coaxial stents at said first and second coaxial walls2 a, 2 b, having a nominal diameter that is the same or substantiallyidentical, and fitted one in (and against) the other;

FIG. 5 is a longitudinal section view of a device of the invention asshown in FIG. 3 , including a multiply-perforated injection-suction tubeas shown in FIG. 5A;

FIG. 5A is a diagrammatic side view in longitudinal section of anembodiment of the end of the injection-suction tube constituted by aportion of multiply-perforated tubes extending in a Z-shape runningalong the suction chamber substantially helically against a face of saidfirst wall or of said second wall of a stent of the anchor element; and

FIG. 6 shows a device of the invention fitted with a connection endpiece7 co-operating with a syringe 8, said endpiece 7 including ananti-reflux valve 7 a and a balloon 7 b having a connection rod 7 c andsuitable for being pushed into the end of the injection-suction tube 6.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a surgical device 1 for anchoring on the mucous membrane ofthe inner wall of the intestine 10, the device comprising a temporaryanchor element 2 constituted by a first and only semi-rigid hollowlongitudinal element defining a wall in the form of a surface ofrevolution around a longitudinal axis XX having a substantiallycylindrical multiply-perforated main portion of substantially circularsection referred to as a “first” wall 2 a, said anchor element 2 beingmade of a material that gives it properties of radial elasticity so asto enable it to be compressed radially into a retracted position and toadopt a said maximum radially expanded position after the radialcompression has been released, whereby said multiply-perforated wallpresents a first outer diameter that can be varied in controlled mannerbetween:

-   -   a minimum first outer diameter D1′ in said radially retracted        position of said first wall, which is preferably no more than 10        mm; and    -   a maximum first outer diameter D1 in said maximally radially        expanded position of said first wall, preferably lying in the        range 18 mm to 45 mm.

Said hollow longitudinal element of said first wall 2 a is a stent ofthe type made by a mesh of spiral-wound metal wires made of nitinol, asshown diagrammatically in FIG. 1A, with the anchoring thereof beingmodifiable in controlled manner as a function of temperature. Itpresents properties of radial expansion that are controlled as afunction of temperature. More precisely, and as a result of theproperties of the nitinol, it expands radially in progressive manner assoon as it is placed at a temperature higher than a temperature of about20° C.

The multiple perforations 2 a-1 of said first wall 2 a correspond to theorifices in the mesh made by the spiral-wound mesh of nitinol wires.

The dimensional data concerning the data D1′ and D1 as given abovecorresponds to dimensions that are appropriate for anchoring the deviceagainst the mucous membrane of the inner wall of the intestine 10 atvarious positions between and including the rectum and the esophagus.

In FIG. 1 , the stent 2 a is covered in a layer 2 d of polyurethane orof silicone, which is itself multiply-perforated at 2 d-1 on the outersurface of 2 a. This layer 2 d protects the intestinal wall 10 byavoiding it becoming incrusted by the outer surface of the stent 2 a.

The entire length of the cylindrical inner surface of said first wall 2a is lined with an independent leakproof layer forming an inner sheath3, with only the longitudinal ends 3 a, 3 b of said inner sheath 3 beingfastened in leaktight manner 4 a, 4 b to said anchor element 2 with thehelp of first leaktight fastener means 4-1 a, 4-1 b constituting anannular gasket of elastomeric adhesive at each said longitudinal end (3a, 3 b) of said inner sheath.

In FIG. 1 , said inner sheath 3 is constituted by a leakproof filmforming a flexible tubular wall.

The device of the invention also includes an outer sheath 7 having atubular wall constituted by a flexible film fastened to said anchorelement 2 at one longitudinal end of said anchor element.

In FIG. 1 , said outer sheath 7 constitutes an extension of said innersheath 3 extending over the outside of said anchor element along thelongitudinal direction of said anchor element.

The device of the invention also has a flexible or semi-rigid tubereferred to as an injection-suction tube 6 that extends outside saidanchor element 2.

Said inner sheath 3 is independent of the inner surface of said firstwall between these two ends 3 and 3 b, so it can be understood that theinner sheath 3 is not excessively tensioned in order to avoid stiffeningthe stent, such that the spacing between said inner sheath 3 and saidmaximum first outer diameter D1 of the first wall 2 a preferably lies inthe range 0.2 mm to 10 mm, more preferably in the range 1 mm to 5 mm,and the space between said inner sheath 3 and said first wall 2 adefines a chamber referred to as the “suction” chamber 5. An open end ofthe injection-suction tube constituted by a portion of tubes 6 a havingmultiple perforations 6 a-1 extends substantially over the entire lengthof said chamber 5 in the longitudinal direction XX of the device. Theinjection-suction tube 6 opens out into said suction chamber 5 bypassing in leaktight manner through the annular elastomer adhesivegasket at the downstream end 3 b of the sheath 3 when the tube 6 isinserted via the anal orifice, or the gasket at the upstream end 3 a ofthe sheath 3 when the tube 6 is inserted via the oral orifice.

Said injection-suction tube 6 and said outer sheath 7 extend outsidesaid anchor element from the same downstream end of said anchor element,and preferably said injection-suction tube 6 and said outer sheath 7 arestuck together on the outside of said outer sheath 7 for anal insertion.

The injection-suction tube 6 serves to inject or suck air or a liquidinto or from the chamber 5 in order to suck the intestinal wall 10against the outer face of the stent 2 a or to separate it therefrom, andmore generally in order to modify the anchoring characteristic of thestent 2 a relative to the intestinal wall 10. The layer 2 d isperforated at 2 d-1 in order to allow the air or the liquid to passthrough.

In FIG. 1 , the portion 6 a of the injection-suction tube 6 inside thechamber 5 may be stuck to the inner face of the first wall 2 a or to theouter face of said outer sheath.

In all embodiments, said first wall 2 a presents:

-   -   a) a length L1 of at least 30 mm, preferably lying in the range        40 mm to 150 mm, and an outer diameter that may be varied in        controlled manner between a minimum outer diameter D1′ in the        retracted radial position of said first wall of at most 10 mm,        and a maximum outer diameter D1 in the maximally radially        expanded position of said first wall lying in the range 18 mm to        45 mm, preferably in the range 20 mm to 35 mm; and    -   b) its upstream longitudinal end with a flared extension 2 c        referred to as a “collar”, defining a wall in the form of a        surface of revolution around said longitudinal axis XX,        presenting a section that is circular and of increasing        diameter, preferably having a length L1′ lying in the range 5 mm        to 30 mm, more preferably a length lying in the range 15 mm to        20 mm, with a maximum diameter DO equal to about 110% of said        maximum first diameter, and more particularly lying in the range        21 mm to 37 mm.

This collar 2 c serves to slow down migration of the device 1 inside theintestine even after its anchoring against the inner wall 10 of theintestine has been eliminated in the main longitudinal portion or outersurface of the first wall 2 a.

In all embodiments, said outer sheath 7 presents, at rest, a length L2downstream from said anchor element 2 of at least 50 cm, preferably atleast 1 m, and an outer diameter lying in the range 18 mm to 45 mm,preferably lying in the range 20 mm to 35 mm.

In FIG. 2 , the device of the invention includes a second stent 2 barranged coaxially inside said first stent 2 a, said second stent 2 bbeing constituted by another small enteral prosthesis formed by a meshof spiral-wound nitinol wires having its outer surface covered in aleakproof film constituting said inner sheath 3, said second wall 2 bdefining a surface of revolution around said longitudinal axis XX havinga main portion that is substantially cylindrical of substantiallycircular section, said second wall presenting a second outer diametersmaller than said first outer diameter of said first wall 2 a, thelongitudinal ends of said second wall 2 b being fastened in leaktightmanner to the longitudinal ends of said first wall 2 a by means of firstleaktight fastener means 4-1 a, 4-1 b constituting an annular elastomeradhesive gasket 4 a, 4 b at each said longitudinal end of said secondwall, so as to define said leaktight suction chamber 5 laterally, saidsecond hollow cylindrical element being made of a material giving itradial elasticity properties such as to enable it to be compressedradially into said retracted position and to adopt a said maximallyradially expanded position after releasing the radial compression insuch a manner that said second outer diameter of said second wall 2 bcan vary in controlled manner between:

-   -   a minimum second outer diameter D2′ in the radially retracted        position of said second wall that is smaller than said minimum        first outer diameter;    -   a maximum second outer diameter D2 in the maximally radially        expanded position of said second wall, that is smaller than said        maximum first outer diameter; and    -   the spacing between said maximum second outer diameter D2 and        said maximum first outer diameter D1 being at least 0.2 mm,        preferably lying in the range 0.2 mm to 10 mm, and more        preferably lying in the range 1 mm to 5 mm.

In this embodiment of FIG. 2 , when air is sucked from the outer end ofthe injection-suction tube 6, the suction through the perforations 6 a-1of the inner tubes portion in the suction chamber 5 causes theintestinal wall 10 to be stuck against the outer surface of the firstwall 2 a via the mesh 2 a-1. However, the space between the inner sheath3 and the outer stent 2 a remains substantially constant, thus making itpossible to avoid clogging the perforations 6 a-1 of the tube portion 6a and thus enabling the vacuum level inside the suction chamber 5 to becontrolled in more reliable and more uniform manner. This also makes itpossible to control the anchor force of the device 1 against the innerwall 10 of the intestine in more reliable and more uniform manner. Inthe embodiment of FIG. 1 , there is a risk of the inner sheath 3sticking against the perforations 6 a-1.

In this embodiment of FIG. 2 , as in the embodiment of FIG. 1 , theinjection-suction tube 6 passes through the first fastener means orannular elastomer adhesive gasket 4-1 b at the downstream end of theanchor element 2.

In FIG. 2 , the portion 6 a of the injection-suction tube 6 inside thechamber 5 may be stuck to the outer face of the inner film or sheath 3over the outer face of the second wall 2 b.

Advantageously, the outer sheath 7 is constituted by an extensiondownstream from the anchor element in the longitudinal direction of saidinner sheath 3.

In a variant, the outer sheath 7 may be fastened at its upstream end tothe same elastomer adhesive gasket 4-1 b or it may be fastened to theouter face of the downstream longitudinal end of the first wall 2 a byoverlying it over a short portion of its length (not shown in thefigures).

In an embodiment (not shown in the figures), the upstream end of thesheath 7 may also cover the outer surface of the second wall 2 b, thusconstituting said inner sheath 3 or only a portion thereof.

FIG. 3 shows a third embodiment in which said inner sheath 3 is appliedfacing the inner surface of the inner stent or second wall 2 b, i.e.inside it and stuck against it at its longitudinal ends. This likewiseprovides a suction chamber 5 presenting substantially permanent radialspacing in the radially expanded position of the first wall 2 a becauseuse is made of a multiply-perforated second wall 2 b as in theabove-described embodiment of FIG. 2 , which wall is constituted by astent of smaller diameter. The second stent or inner stent 2 b defines asaid second multiply-perforated wall 2 b interposed between said innersheath 3 and said first wall 2 a. The end of said injection-suction tube6 a opens out into said suction chamber 5 between said inner sheath 3and said second wall 2 b, said inner sheath 3 being constituted by anupstream extension of said outer sheath 7 constituted by a flexibletubular wall, as in FIG. 1 .

In the embodiment of FIG. 3 , the portion 6 a of the injection-suctiontube 6 that is interposed between the inner sheath 3 and the second wall2 b inside the chamber 5 may be stuck against the inner face of thesecond wall 2 b. When air is sucked through the openings 6 a-1 of thetube portion 6 a in the chamber 5, the flexible sheath 3 is stuckagainst the tube 6 a and the intestinal wall 10 is stuck against theouter face of the outer stent 2 a, but the space between the two coaxialstents 2 a and 2 b is kept constant, as described above, with a spacingof at least 0.2 mm to 10 mm, and preferably lying in the range 1 mm to 5mm, in the radially extended position of said stent. This leads to thesame advantage as in the embodiment of FIG. 2 in terms of the ease, theuniformity, and the reliability with which the anchoring of the stent 2a relative to the intestinal wall 10 can be controlled.

In the embodiment of FIG. 3 , the annular elastomer adhesive gasket 4 a,4 b at each longitudinal end of the main portion of the anchor element2, i.e. at each longitudinal end 3 a, 3 b of the inner sheath 3 and ofthe first and second walls 2 a and 2 b, is constituted by a firstannular gasket portion 4-1 a, 4-1 b between the sheath 3 c and thesecond wall 2 b, and by a second annular gasket portion 4-2 a, 4-2 bbetween the two coaxial stents constituting the first wall 2 a and thesecond wall 2 b.

FIG. 4 shows an embodiment with two coaxial stents of nominal diametersfor their main portions that are substantially identical. Each stent hasa collar 2 c, 2 c-1, 2 c-2 at one of its longitudinal ends, as describedabove, and the two stents 2 a, 2 b are engaged coaxially one inside theother head to tail so that the anchor element 2 has a collar at each ofits longitudinal ends.

The fact that both stents 2 a and 2 b present substantially identicalnominal diameters, i.e. maximum outer diameters D1 and D2, means thatthe inner stent 2 b has its cylindrical main portion constituting saidsecond wall 2 b engaged as a force-fit against the inner surface of thecylindrical main portion of the first stent or first wall 2 a. The twostents are stuck one against the other at their longitudinal ends oftheir said facing cylindrical main portions or first and second walls 2a, 2 b.

As shown in FIG. 3 , the inner sheath 3 is pressed against the inside ofthe inner stent, being stuck to said second wall 2 b, and the innersheath 3 thus constitutes the extension of the outer sheath 7.

As in FIG. 3 , the injection-suction tube 6 is pressed against the innersurface of the second wall 2 b between the second wall 2 b and the innersheath 3.

More precisely, in FIG. 4 , the second wall 2 b or inner stent presentsa collar 2 c-1 at its upstream end, while the outer stent or first wall2 a presents a collar 2 c-2 at its downstream end, the first and secondwalls 2 a, 2 b overlapping over their entire length.

Thus, because the downstream collar 2 c-2 extends the outer stent, it ispossible to place the injection-suction tube 6 so that it extendsdownstream from the anchor element 2 so that its open end 6 a opens outeither into the space between the inner sheath 3 and the second wall 2 bof the inner stent, as shown in FIG. 4 , or else in a variant that isnot shown, with the open end of the injection-suction tube 6 opening outinto the space between the two stents. More precisely, the portion 6 aof the tube 6 may be interposed between the first and second walls 2 a,2 b, i.e. it may be stuck against the outer face of the second wall 2 b.

This FIG. 4 embodiment preserves sufficient space between the innersheath and the intestinal wall 10, thus avoiding clogging of theperforations 6 a in the end of the injection-suction tube 6. Inaddition, it imparts optimum stiffness to the anchor element 2 andprovides stabilization of sufficient length in the intestinal wallbefore migrating after the digestive process has restarted.

FIG. 5A is a diagram showing an embodiment of the end of theinjection-suction tube 6 constituted by a tube portion 6 a havingmultiple perforations 6 a-1, the tube portion extending substantiallyhelically against the inner face of said second wall 2 b, as shown inFIG. 5 , following a zigzag or a Z-shaped line and running along theentire length of the suction chamber 5. This type of zigzag tube ispressed against the inner face of the second wall 2 b and is stuckthereto.

The zigzag or Z-shaped multiply-perforated tube portion 6 a within thechamber 5 may also be pressed against and stuck to the inner surface ofthe second wall 2 a or the outer surface of the second wall 2 b in theembodiment of FIG. 2 , by making it run helically lengthwise in thedirection XX of the annular chamber 5.

Three other variants of the device that are not shown are possible:

-   -   1) a stent 2 a with two collars and a stent 2 b without a        collar;    -   2) a stent 2 a without a collar and a stent 2 b with only one        collar; and    -   3) a stent 2 a without a collar and a stent 2 b with two        collars.

FIG. 6 shows the outer free longitudinal end of said injection-suctiontube 6 reversibly connected to a connection endpiece 7 including ashutter device consisting in an anti-reflux valve 7 a, and including anindicator device for indicating the degree of vacuum in the chamber 5,which device is constituted by a balloon 7 b.

More precisely, the connection endpiece 7 comprises a rigid connectionrod 7 c extended by said indicator balloon 7 b itself co-operating withand extended by the anti-reflux device 7 a.

The connection endpiece 7 may be connected to a suction appliance, e.g.a syringe 8 at the free end of the anti-reflux device 7 a. A connectionendpiece 7 of this type is sold by the supplier Teleflex Medical Company(USA) under the reference Ruschlit PVC No.

The anti-reflux device 7 a comprises an outer hollow cylinder 7 a-1 andan inner hollow central cylinder 7 a-2. The hollow central cylinder 7a-2 is guided inside the outer cylinder 7 a-1 by a first abutment 7 a-3secured to the inner wall of the outer cylinder 7 a-1 and including acentral orifice 7 a-4 through which said hollow central cylinder 7 a-2passes. A second abutment 7 a-5 is secured to said hollow centralcylinder 7 a-2, and a spring 7 a-6 is secured by respective ends to saidfirst abutment 7 a-3 and to said second abutment 7 a-5 so that in theextended position of said spring, a third abutment 7 a-7 secured to theother end of said hollow central cylinder 7 a-1 comes into abutmentagainst a face of the first abutment 7 a-3. When the end of the syringe8 is fitted in the flared end 7 a-8 of said hollow central cylinder 7a-1, the bearing force of the syringe serves to compress the spring andseparate said first and third abutments 7 a-3 and 7 a-7 so that the airinjected by the syringe 8 can flow from an orifice 7 a-8 at the end ofsaid hollow central cylinder via the passage 7 a-9 between said firstand third abutments 7 a-3 and 7 a-7. After the syringe 8 has beenremoved, the spring 7 a-6 returns to its extended position and the thirdabutment 7 a-7 comes to press against the first abutment 7 a-3 and shutoff any passage for air between the outside of the anti-reflux device 7a and the inside of the balloon 7 b.

By sucking air into the perforated mini-tube 6 a using the syringe 8 viathe connection endpiece 7, a vacuum is created in the suction chamber 5.The intestinal mucous membrane 10 is attracted to the outer surface ofthe stent 2 a under the effect of the suction, thereby increasing theanchoring of the device 1. Conversely, this effect is canceled byinjecting air or a liquid solution into said suction chamber 5 using thesame mini-tube 6 from the outer free longitudinal end of theinjection-suction tube 6.

As mentioned above, when a liquid solution is injected into the suctionchamber 5, the temperature of the solution can be used to modify thetemperature and thus the shape and the stiffness of the first wall 2 a,which is made of nitinol alloy. More particularly, at temperatures lowerthan 15° C., nitinol becomes flexible and malleable, such thatintroducing a cold liquid in the range 0° C. to 15° C. in the chamber 5can make the stent 2 a malleable, and possibly also the stent 2 b,thereby facilitating migration of the stent on passing through theanastomosis or through a zone of narrowing, for example.

The flexible sheaths 3 or 7 may be made using a mixture of various typesof silicone, e.g. of the LSR, RTV, and gel types, as described above.

WO 2010/092291 describes introducing the device of the invention. It isintroduced while in retracted form by means of an introducer 4 that isconstituted by a semi-rigid plastics tube suitable for being deformedand having a diameter lying in the range 3 mm to 20 mm, preferably inthe range 10 mm to 15 mm, and a length lying in the range 70 cm to 220cm, with the anchor element being inserted therein in its retractedshape, said sheath being positioned downstream from the anchor elementinside the guide tube of the introducer. Once the guide tube of theintroducer has reached the implantation site, e.g. about 1 m upstreamfrom the anastomosis, the anchor element may be moved out from the endof the introducer and it may take up an expanded position. It should beobserved that the time required for introducing and moving the anchorelement introducer to the implantation site is in practice shorter thanthe time after which said anchor element is subjected to radialexpansion as a result of its temperature increasing because it is insidethe body.

In its initial shape, in which it is closed and housed inside theintroducer, the stent (s) 2 a, 2 b present (s) a diameter that is verysmall, in particular lying in the range 5 mm to 15 mm. It is passedthrough the anastomosis, and then into the upstream intestine. Thesurgeon assesses progress of the introducer and whether it is properlypositioned by palpating the introducer through the walls of theintestine and viewing the stent during its expansion. Once released inthe lumen of the intestine, the stent progressively returns to its finaldiameter. It can be held temporarily in place by the surgeon pinchingthe stent through the walls of the intestine. The introducer is thenwithdrawn. The sheath 7 unfolds spontaneously and progressively as theintroducer is withdrawn. The introducer passes back through theanastomosis and then through the anal orifice in the reverse direction,thereby completely releasing the sheath 7. After an average period offour days to six days, and under the effect of intestinal contractions,the unit comprising the stent, the outer sheath, and theinjection-suction tube migrates progressively towards the anal orificefrom its upstream anchor site, which site is far enough upstream fromthe anastomosis, preferably via at least 20 cm of intestine length, toensure that the stent reaches the anal orifice five or six days later,only after the digestive process has restarted, after which the deviceis eliminated with fecal matter.

The device of the invention may be combined with other means for apurpose other than protecting an anastomosis.

In particular, it may be used for all applications requiring anchoringin the intestine, in particular for the purpose of controlling suchanchoring better.

Mention is made in particular of devices for increasing the sensation ofbeing sated, as described in US 2008/0208357.

What is claimed:
 1. A negative pressure anchor for an intestine that hasa flow therethrough, an anastomosis, and an anchor position upstreamfrom the anastomosis, the negative pressure anchor comprising: a tubularanchor comprising an outer surface and an inner surface, the tubularanchor configured to be disposed in the intestine such that the outersurface is configured to contact an intestinal wall at the anchorposition upstream from the anastomosis, the tubular anchor configured toattach to a sheath in a leaktight manner, such that an end of the sheathextends upstream from a downstream end of the tubular anchor and thesheath extends beyond the anastomosis to cover and protect theanastomosis from matter flowing through the tubular anchor and thesheath and thereby allow the flow of the intestine to pass through thetubular anchor and the sheath without contacting the anastomosis and theintestine downstream from the sheath; and a tube coupled to the tubularanchor and a suction source, the tube configured to create a leaktightseal between the outer surface of the tubular anchor and the intestinalwall at the anchor position upstream from the anastomosis, whileallowing the flow of the intestine to pass through the tubular anchor,wherein the tubular anchor comprises radial expansion properties suchthat the outer surface of the tubular anchor is configured to, duringperistalsis, continue to contact the intestinal wall in the leaktightmanner.
 2. The negative pressure anchor of claim 1, further comprising afirst annular gasket disposed at an upstream end of the tubular anchorand a second annular gasket disposed at the downstream end of thetubular anchor.
 3. The negative pressure anchor of claim 2, wherein thefirst and second annular gaskets form the leaktight seal with theintestinal wall at the anchor position upstream from the anastomosis. 4.The negative pressure anchor of claim 1, wherein the tube is coupled toa connection endpiece.
 5. The negative pressure anchor of claim 4,wherein the connection endpiece comprises a valve.
 6. The negativepressure anchor of claim 1, wherein the tubular anchor has a diameter,in an expanded position, selected such that the outer surface of tubularanchor contacts the intestinal wall for anchoring.
 7. The negativepressure anchor of claim 6, wherein the diameter is in a range of 18 mmto 45 mm.
 8. The negative pressure anchor of claim 1, further comprisingthe suction source, wherein the negative pressure is applied to the tubeby the suction source to control or modify anchor force of the tubularanchor against the intestinal wall.
 9. The negative pressure anchor ofclaim 1, wherein the sheath has a length to extend downstream from thetubular anchor to outside an anal orifice.
 10. The negative pressureanchor of claim 1, wherein the tubular anchor has a length in a range of40 mm to 150 mm.
 11. The negative pressure anchor of claim 1, whereinthe sheath is comprised of biocompatible synthetic material.
 12. Thenegative pressure anchor of claim 1, further comprising an additionaltube for applying negative pressure at the tubular anchor.
 13. Thenegative pressure anchor of claim 1, wherein the tubular anchorcomprises a covering configured to increase a coefficient of friction ofthe outer surface of the tubular anchor to resist migration.
 14. Thenegative pressure anchor of claim 13, wherein the covering comprisestexturing on the outer surface of the tubular anchor.
 15. The negativepressure anchor of claim 1, wherein the tubular anchor comprises acovering made of biocompatible synthetic material.
 16. The negativepressure anchor of claim 1, wherein the tubular anchor comprises asecond stent arranged coaxially inside a first stent.
 17. A deliverysystem comprising: a tubular outer shell configured to hold the negativepressure anchor of claim 1 in a retracted position; and a pusher tubewithin the tubular outer shell, wherein the negative pressure anchor isconfigured to be introduced into the intestine via the anal orifice andpushed out the tubular outer shell via the pusher tube for anchoring thetubular anchor in the intestine upstream of the anastomosis.
 18. Thedelivery system of claim 17, wherein the tubular outer shell of thedelivery system is configured to compress the tubular anchor and holdthe tubular anchor therein in the retracted position.
 19. The negativepressure anchor of claim 1, wherein the tubular anchor comprises aplurality of perforations to permit fluid to pass therethrough.
 20. Thenegative pressure anchor of claim 2, wherein the tube is configured tocreate the leaktight seal via application of negative pressuretherethrough by the suction source such that the tubular anchor resistsmigration due to frictional forces between (i) the outer surface of thetubular anchor and the first and second annular gaskets of the tubularanchor, and (ii) the intestinal wall of upstream from the anastomosis.21. The negative pressure anchor of claim 1, wherein the tubular anchoris semi-rigid.
 22. The negative pressure anchor of claim 1, wherein thetubular anchor comprises a shape memory material.
 23. The negativepressure anchor of claim 1, wherein the tubular anchor comprises a meshof spiral-wound metal wires made of nitinol.
 24. The negative pressureanchor of claim 1, wherein the tubular anchor comprises a stent.
 25. Thenegative pressure anchor of claim 1, wherein the tubular anchorcomprises a flared end region having a greater diameter than acylindrical region.
 26. The negative pressure anchor of claim 1, whereinthe sheath comprises an inner sheath that is positioned within thetubular anchor and an outer sheath that defines an outer surface of thenegative pressure anchor downstream from the tubular anchor, and whereinthe outer sheath is an extension of the inner sheath.
 27. The negativepressure anchor of claim 1, wherein the sheath is a flexible tube. 28.The negative pressure anchor of claim 1, wherein the tubular anchor isconfigured to define a suction chamber formed by the sheath and leaktight fasteners at opposing longitudinal end regions of the tubularanchor, and wherein the tube passes in a leak tight manner through oneof the leak tight fasteners for applying negative pressure in thesuction chamber.
 29. A method for anchoring a sheath in an intestinethat has a flow therethrough, an anastomosis, and an anchor positionupstream from the anastomosis, the sheath being in connection with atubular anchor and extending downstream from the tubular anchor, thetubular anchor having an inner surface facing the sheath and an outersurface for contacting an inner wall of the intestine, the tubularanchor configured to attach to the sheath in a leaktight manner, suchthat an end of the sheath extends upstream from a downstream end of thetubular anchor and the sheath extends beyond the anastomosis to coverand protect the anastomosis from matter flowing through the tubularanchor and the sheath and thereby allow the flow of the intestine topass through the tubular anchor and the sheath without contacting theanastomosis and the intestine downstream from the sheath, the methodcomprising: inserting the tubular anchor in the intestine, such that thetubular anchor is positioned at the anchor position upstream from theanastomosis and the sheath covers and protects the anastomosis frommatter flowing through the tubular anchor and the sheath; and applyingnegative pressure to a region between the outer surface of the tubularanchor and the intestinal wall at the anchor position upstream from theanastomosis to create a leaktight seal between the outer surface of thetubular anchor and the intestinal wall, while allowing the flow of theintestine to pass through the tubular anchor, wherein the tubular anchorcomprises radial expansion properties such that the outer surface of thetubular anchor is configured to, during peristalsis, continue to contactthe intestinal wall in the leaktight manner.
 30. An anchoring system forprotecting an anastomosis in an intestine, the anchoring systemcomprising: a tubular anchor comprising an outer surface, the tubularanchor configured to be disposed in the intestine upstream of theanastomosis in the intestine; a first annular gasket disposed at anupstream end of the tubular anchor; a second annular gasket disposed ata downstream end of the tubular anchor; a tube in fluid connection withthe outer surface of the tubular anchor; and a sheath in connection withthe tubular anchor, the sheath defining a lumen, the sheath having anupstream end positioned upstream of a downstream end of the tubularanchor, the upstream end of the sheath positioned upstream of the secondannular gasket, wherein the sheath extends downstream from thedownstream end of the tubular anchor to cover and protect theanastomosis in the intestine from matter flowing through the lumen ofthe sheath and the tubular anchor, wherein the anchoring system isconfigured to apply negative pressure by an external suction source tothe tube to form a leaktight configuration of the tubular anchor thatresists migration of the tubular anchor due to frictional forces between(i) the outer surface of the tubular anchor and the first and secondannular gaskets of the tubular anchor, and (ii) an inner wall of theintestine upstream from the anastomosis, and wherein the tubular anchorcomprises radial expansion properties such that the outer surface of thetubular anchor is configured to, during peristalsis, continue to contactthe intestinal wall in the leaktight manner.